Compression tests

What is a compression test?

A compression test is a mechanical test which consists in analyzing the variations in dimension of a solid sample when a compressive force is applied to it. Indeed, the size of the solid samples varies more or less significantly when a compressive force is applied to them. Their width also tend to increase.

These tests are often carried out in the same context as tensile tests, for which the force applied is opposite.

What are the different test parameters?

Compression tests can be performed by varying a number of parameters:

• Applied force regulated in a constant or progressive manner
• Length variation read, or controlled
• Ambient temperature, or regulated over a wide range

The choice of these parameters will be made according to your needs and your samples.

What are the parameters determined during the compression tests?

When a compressive force is applied to a material, a greater or lesser variation in length is measured. When the force increases, several phenomena can be observed.

First of all, a rupture of the material can be observed. The value of force, or rather of pressure undergone by the sample at the time of rupture is the compressive strength. It is expressed in Pa, MPa or Gpa.

Under the effect of compression, long enough material can bend. The deflection is then measured, which is the displacement of the maximum sample in the direction opposite to the compression force.

Compression tests also measure the hardness of materials. This measurement is carried out with a force applied to a small surface of the material, and by measuring the height of penetration of the element in the material according to the force applied.